1. Field of the Invention
The present invention relates to an engine mounting structure for a motorcycle.
2. Description of Background Art
There is a motorcycle in which an engine is mounted to a vehicle body frame and a rear wheel supporting swing arm is vertically swingably mounted to the engine. See, Japanese Patent Laid-open No. 2002-79983, FIGS. 5 and 6.
The conventional motorcycle shown in Japanese Patent Laid-open No. 2002-79983 includes an engine mounting structure in which a cross member is bridgingly disposed between a left-right pair of frame members of the vehicle body frame, a vehicle body side bracket is provided at a nearly intermediate portion of the cross member with both sides in the vehicle body width direction of the vehicle body side bracket being clamped between a left-right pair of engine-side brackets provided on the engine. The engine is mounted to the vehicle body side bracket through engine support bolts and an elastic member with the rear wheel supporting swing arm being vertically swingably mounted to the engine.
When a motorcycle is operated, the rear wheel is vibrated according to the conditions of the road surface, and the vibration (hereinafter referred to as “the operating vibration”) is transmitted from the rear wheel to the engine through the swing arm. Since the elastic member moderates the operating vibration, it is difficult for the vibration to be transmitted from the engine to the vehicle body frame.
In such a configuration, in order to further reduce the operating vibration transmitted from the engine to the vehicle body frame, it may be contemplated to lower the hardness of the elastic member. However, in the motorcycle, it is required to secure the feeling of unity between the vehicle body frame and the engine in the cases of, for example, operating while turning. Therefore, there is a limitation in simply lowering the hardness of the elastic member.